The snack food company Mondelez International recalled some of its Ritz cracker products on Saturday after a whey powder supplier identified a potential salmonella risk.

As of Monday afternoon, there had been no reports of illnesses connected to the products, a Mondelez spokeswoman said. The recall was limited to the United States, including Puerto Rico and the U.S. Virgin Islands, according to a news release on Saturday. It was “being conducted with the knowledge of the U.S. Food and Drug Administration,” the release said.

“We are taking this step as a voluntary, precautionary measure,” Kimberly Fontes, the spokeswoman, said in an email on Monday.

Salmonella can result in diarrhea, fever and abdominal cramps, typically for a duration of four to seven days, according to the Centers for Disease Control and Prevention. The C.D.C. estimates the bacteria causes 1.2 million illnesses, 23,000 hospitalizations and 450 deaths in the United States each year.

There have been several outbreaks this year. One linked to Kellogg’s Honey Smacks cereal sickened 100 people and hospitalized 30 in June and July, according to the C.D.C, and dozens of people fell ill from pre-cut watermelon in June.

Romaine lettuce contaminated with E. coli was responsible for at least five deaths, with people becoming sick in 36 states.

Randy Worobo, a professor of food microbiology at Cornell University, said the lack of illnesses suggested Mondelez was being proactive by issuing the recall, reducing the chances its consumers might get sick.

“Ritz was being on the very cautious side,” he said.

Tainted food, or even the possibility thereof, presents a bevy of challenges to businesses, on top of the immediate expenses of recalling a product. Chipotle, for one, took a long-lasting hit to public confidence after a series of contaminations in 2015.

How does food typically become contaminated?

It is usually some form of human or mechanical error, sometimes at the companies that supply ingredients to the big-name food manufacturers.

Mr. Worobo said it can often be the result of a breach in cleaning or sanitation protocol. It could also derive from inadequate processing, like cooking at too low a temperature because of a faulty thermometer.

How are issues detected?

Companies often send their finished product away for testing, but it is far from a guarantee that such testing would identify contaminations.

“Imagine you have a jar full of M&M’s, and they’re all the same color, and you have one that’s not the same color,” Mr. Worobo said. “If you take a handful out of that container, what are the chances of getting the one colored M&M? Low, right?”

If testing does not reveal contamination, the company might not become aware until consumers get sick. Once there’s a cluster of people who fall ill, officials can determine what ingredient the patients had in common.

It might seem as if food is contaminated more often than it was years or decades ago, based on how many times widespread recalls make news. But Mr. Worobo said it is not because of a decrease in food safety standards — it is just easier to detect problems than it used to be because of better technology.

What is the risk if I ate the product?

If you have purchased one of the tainted food items, it is not a sure thing you would fall sick. But there is no uniform way of knowing exactly how likely it would be.

The contamination could have affected a large or minuscule percentage of the products on shelves.

“Not every leaf of the romaine lettuce is going to be contaminated,” Mr. Worobo said, referring to an E. coli outbreak that was tied to the deaths of five people this year.

Your body’s response could also depend partly on the health of your immune system, with children and the elderly more susceptible, Mr. Worobo said.

How can I know what has been recalled?

While not every recall gets a news release, the F.D.A. seeks publicity for recalls “only when it believes the public needs to be alerted to a serious hazard,” according to a page last updated on its website in late 2017.